[gmx-users] SSE4 → AVX2

[nicola staffolani]

@ Szilárd: g++ (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3

But I have only one machine...

I know that Google knows more, the problem is that I have a finite amount
of time to solve my problems and I have to make a decision on how to spend
it ;) (which is, however, in conflict with the fact that, having already
come all this way, then I am a priori curios to know what comes next ;)



2014-08-27 14:04 GMT+02:00 Szilárd Páll <pall.szilard at gmail.com>:

> --
> Szilárd
>
>
> On Wed, Aug 27, 2014 at 12:32 PM, nicola staffolani
> <n.staffolani at unitus.it> wrote:
> > Thanx Szilárd!
> >
> > The concept of cross compilation is not perfectly 100% clear to me :s
>
> Briefly: given machine A and B (with different architectures), compile
> binary for B on machine A (e.g. compiling for cluster nodes).
>
> Google knows even more.
>
> > software: GROMACS 4.6.5
> > hardware: Intel® Core™ i7-4790 CPU @ 3.60GHz × 8
> > message: Compiled acceleration: SSE4.1 (Gromacs could use AVX_256 on this
> > machine, which is better)
> >
> > Have I given you the info you had requested?
>
> If you are compiling on that machine, I suspect you have an outdated
> compiler. What compiler are you using?
>
> >
> >
> >
> >
> > 2014-08-27 12:00 GMT+02:00 Szilárd Páll <pall.szilard at gmail.com>:
> >
> >> Normally the highest supported SIMD instructions set, which is in your
> >> case AVX2, is detected during configuration phase. The fact that you
> >> are getting that message means that:
> >> - you are cross-compiling on an SSE4.1 node (e.g. cluster head node)
> >> for AVX2 machines;
> >> - your compiler does not support AVX/AVX2 and SSE4.1 was chosen as
> >> fallback; cmake should have warned about this during configuration.
> >>
> >> What is your hardware/software setup? Using -DGMX_SIMD=AVX2 should
> >> work in the former case.
> >>
> >> Cheers,
> >>
> >> --
> >> Szilárd
> >>
> >>
> >> On Wed, Aug 27, 2014 at 10:44 AM, nicola staffolani
> >> <n.staffolani at unitus.it> wrote:
> >> > Dear Gromacs users & developers,
> >> >
> >> > my computer tells me that, if I'd use AVX_256 instead of SSE4, then my
> >> > simulations would be done much faster. Which changes in which files
> do I
> >> > have to do in order to achieve this? I have serched the mailing list
> but
> >> > couldn't find the explicit answer: I warn you that I am not so much
> of a
> >> > geek, therefore suggesting me, for example, to change the path,
> without
> >> > telling me which precise actions I have to carry on (for example, as
> >> > already said, which lines I have to change/add in which file) in
> order to
> >> > achieve this, will only generate the next email from my side and then,
> >> > since by then you will have already started answering me, you will
> lose
> >> > more time answering me back than if you would have precisely
> described in
> >> > the first reply the order of precise actions needed to be done in
> order
> >> to
> >> > achieve the goal ;)
> >> >
> >> > Thank you for helping and have a nice day/night,
> >> >
> >> > Nicola
> >> > --
> >> > Nicola Staffolani PhD
> >> > Biophysics & Nanoscience Centre CNISM <
> http://www.unitus.it/biophysics>
> >> > Università della Tuscia
> >> > Largo dell'Università s.n.c., I-01100 Viterbo
> >> > email: n.staffolani at unitus.it
> >> > tel.: +39 0761 35 70 27; fax: +39 0761 35 71 36
> >> > --
> >> > Gromacs Users mailing list
> >> >
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> >
> >
> >
> > --
> > Nicola Staffolani PhD
> > Biophysics & Nanoscience Centre CNISM <http://www.unitus.it/biophysics>
> > Università della Tuscia
> > Largo dell'Università s.n.c., I-01100 Viterbo
> > email: n.staffolani at unitus.it
> > tel.: +39 0761 35 70 27; fax: +39 0761 35 71 36
> > --
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-- 
Nicola Staffolani PhD
Biophysics & Nanoscience Centre CNISM <http://www.unitus.it/biophysics>
Università della Tuscia
Largo dell'Università s.n.c., I-01100 Viterbo
email: n.staffolani at unitus.it
tel.: +39 0761 35 70 27; fax: +39 0761 35 71 36